Yea, honestly. The most common answer I hear is always to quit and find a new job. And on HN especially, where we all dive into systems engineering to build reliable pipelines and fix bugs to ensure they don't happen ever again... it's so weird to see the same ppl just say quit. Because that literally solves nothing for anyone. The new job may not be better, or the manager at the new job may quit and be replaced by a really bad boss, the current job is still sucks for current and future employees, and like the above poster said, the boss won't learn a thing and continue to shit on any employee under their command at every job they're at.
Unions balance that power out, so that it can address exactly those core issues: the boss's attitude as an immediate solution for you as the affected employee, and the company's culture as a more permanent and systems-wide solution. This is a better patch than to just quit, at the very least.